Camera module and method of manufacturing the camera module

ABSTRACT

A camera module includes an image sensor chip including a substrate having first and second opposite surfaces and a ground pad on the first surface, a housing surrounding the sides of the image sensor chip but which leaves the second surface of the image sensor chip exposed, an electromagnetic wave-shielding film united with the housing, and an electrical conductor electrically connected to the ground pad. The camera module also has an optical unit disposed on the first surface of the image sensor chip in the housing to guide light from an object to the image sensor chip. The electrical conductor extends through a side of the housing. The conductor also contacts the electromagnetic wave-shielding film to electrically connect the ground pad and the electromagnetic wave-shielding film.

PRIORITY STATEMENT

This is a Divisional of U.S. non-provisional application No. 13/044,601,filed Mar. 10, 2011, which claims priority under 35 U.S.C. §119 toKorean Patent Application No. 2010-0046324, filed on May 18, 2010 in theKorean Intellectual Property Office (KIPO).

BACKGROUND

The inventive concept relates to a camera module having an image sensorchip and to a method of manufacturing such a camera module.

Recently, high resolution camera modules have been widely used indigital devices such as digital cameras, camera phones, etc. The cameramodule includes an image sensor for converting image information intoelectrical information. To this end, the image sensor includessemiconductor devices capable of converting photons to electrons.Examples of the image sensor are charge coupled devices (CCD) andcomplementary metal oxide silicon (CMOS) image sensors (CIS). Becausethe digital device includes various semiconductor devices, the digitaldevice is susceptible to electromagnetic interference.

SUMMARY

According to an aspect of the inventive concept, there is providedcamera module comprising an image sensor chip, a housing extendingaround the sides of the image sensor chip, an electromagneticwave-shielding film united with the housing, an optical unit disposed inthe housing, and an electrical conductor extending through a side of thehousing. The image sensor chip includes a substrate having first andsecond opposite surfaces, and a ground pad on the first surface. Thefirst surface of the substrate of the image sensor chip, i.e., thesurface bearing the ground pad, faces the interior of the housing andthe second surface is exposed to the environment outside the housing.The optical axis of the optical unit intersects the image sensor chip sothat light propagating along the axis, e.g., focused by the opticalunit, is incident on the active region of the image sensor chip. Theelectrical conductor that extends through a side of the housingelectrically connects the ground pad and the electromagneticwave-shielding film.

According to another aspect of the inventive concept, there is provideda camera module comprising a housing, and a chip surrounded by thehousing and comprising a substrate having a first surface facing theinterior of the housing and a second surface exposed to the environmentoutside the housing, an image sensor exposed at the first surface of thesubstrate and comprising electronic circuitry, and pads of electricallyconductive material disposed on the first surface of the substrate,wherein the pads are connected to the circuitry of the image sensor andinclude a pad for grounding the chip disposed on the first surface ofthe substrate of the chip. Furthermore, an optical unit for directinglight onto an image sensor of the chip is contained by the housing. Inparticular, the optical axis of the optical unit intersects that part ofthe image sensor which is exposed at the first surface of the substrateof the chip. Thus, light propagating along the optical axis impinges theimage sensor. The camera module also has an electrical conductorextending through a side wall of the housing and electrically connectedto a ground pad of the chip.

According to still another aspect of the inventive concept, there isprovided a method of manufacturing a camera module, comprising:providing an image sensor chip including a substrate and a ground pad ona first surface of the substrate, providing a housing having athrough-hole extending through a side thereof, providing a transparentmember, providing the housing with an electromagnetic wave-shieldingfilm, assembling the image sensor chip and the transparent member to thehousing, and forming an electrical conductor that is electricallyconnected to the ground pad of the image sensor chip. The image sensorchip, transparent member and housing are assembled to one another insuch a sequence, etc., that the first surface of the substrate of theimage sensor chip faces the interior of the housing, the transparentmember is disposed on the first surface of the substrate, the secondsurface of the substrate of the image sensor chip is exposed to theenvironment outside the housing, and the ground pad is exposed to theenvironment outside the housing via the through-hole extending throughthe side of the housing. The through-hole is filled with conductivematerial to form the conductor.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept will be more clearly understood from the followingdetailed description of preferred embodiments thereof made inconjunction with the accompanying drawings.

FIG. 1 is a cross-sectional view of an embodiment of a camera module inaccordance with the inventive concept.

FIG. 2 is an enlarged view of portion “A” in FIG. 1 of the cameramodule.

FIG. 3 is a cross-sectional view taken along line III-III′ in FIG. 2.

FIGS. 4 to 8 are cross-sectional views and together illustrate a methodof manufacturing a camera module according to the inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various embodiments and examples of embodiments of the inventive conceptwill be described more fully hereinafter with reference to theaccompanying drawings. In the drawings, the sizes and relative sizes andshapes of elements and layers may be exaggerated for clarity. Inparticular, the cross-sectional illustrations are schematic. Also, likenumerals designate like elements throughout the drawings.

Furthermore, spatially relative terms, such as “side”, are used todescribe the orientation shown in the drawings for ease of descriptionand are not necessarily limiting because embodiments according to theinventive concept can assume orientations different than thoseillustrated in the drawings when in use.

It will also be understood that when an element or layer is referred toas being “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer orintervening elements or layers may be present. In contrast, when anelement or layer is referred to as being “directly on” or “directlyconnected to” another element or layer, there are no interveningelements or layers present.

Other terminology used herein for the purpose of describing particularexamples or embodiments of the inventive concept is to be taken incontext. For example, the terms “comprises” or “comprising” when used inthis specification specifies the presence of stated features orprocesses but does not preclude the presence or additional features orprocesses.

An example of a camera module in accordance with the inventive conceptwill now be described with reference to FIGS. 1-3.

The camera module 100 includes an image sensor chip 110, an optical unit130 provided on the image sensor chip 110 and a housing 140 containingthe image sensor chip 110 and the optical unit 130.

In this example, the image sensor chip 110 includes a CMOS(complementary metal oxide silicon) image sensor. The CMOS image sensor(CIS) has an active pixel region for image pickup and a CMOS logicregion for processing signals output from the active pixel region. Theactive pixel region may include a photodiode and a MOS transistor. TheCMOS logic region may include a plurality of CMOS transistors.

An example of the general structure of the image sensor chip 110 willnow be described. The image sensor chip 110 includes a substrate havinga first surface 110 a and a second surface 110 b opposite to the firstsurface 110 a. The first surface 110 a is an active surface at whichcircuit elements of the image sensor chip are provided. A ground pad 112and a plurality of chip pads 114 are also disposed on the first surface110 a on the image sensor chip 110. The pads are, for example, spacedalong the periphery of the image sensor chip 110. The image sensor chip110 also has outer connection pads 116 on the second surface 110 b ofthe substrate.

In this example, the image sensor chip 110 has conductive vias (TSV) 118extending through the substrate and electrically connecting the chippads 114 to the outer connection pads 116. A plurality of outerconnection members 320, such as solder balls, may be disposed on theouter connection pads 116. Accordingly, the image sensor chip 110 may bemounted on a circuit board (not illustrated) by means of the outerconnection members 320.

In an example of this embodiment, the camera module 100 also has atransparent member 120 on the image sensor chip 110. The transparentmember 120 serves as an optical filter. To this end, the transparentmember 120 may be a layer of glass. The glass or other transparentmaterial may be in the form of a sheet adhered to the image sensor chip110 by an adhesive film.

The transparent member 120 may have a recess 122 in which the ground pad112 of the image sensor chip 110 is received. Thus, in this case, theopening 122 is provided in the outer periphery of a lower surface of thetransparent member 120 adjacent the outer periphery of the image sensorchip 110. In particular, the recess 122 may form a step in the outerperiphery of the transparent member 120. The recess 122 of thetransparent member 120 is in open communication with a through-hole 142of the housing 140 to provide a path along which the ground pad 112 canbe connected to an external ground.

For example, the through-hole 142 extends through a side of the housing140, and is contiguous with the recess 122 in the transparent member120. To this end, at least part of the through-hole 142 is located at alevel above the upper surface 110 a of the substrate of the image sensorchip 110. Accordingly, the ground pad 112 of the image sensor chip 110may be disposed along the path defined by the through-hole 142 and therecess 122.

The optical unit 130 is disposed on the image sensor chip 110. In thisexample, the optical unit 130 is disposed on the transparent member 120.The optical unit 130 includes at least one lens for guiding light froman object to the image sensor chip 110. Accordingly, the optical unit130 focuses light from the object on the image sensor chip 110.

In this embodiment, the housing 140 surrounds the image sensor chip 110,the transparent member 120 and the optical unit 130. In this respect,the image sensor chip 110, the transparent member 120 and the opticalunit 130 may together have the form of a pillar whose outer contour (orcross section) is square. In this case, the inner contour (crosssection) of the housing 140 is square and complementary with respect tothe outer contour of the pillar. Furthermore, the housing 140 exposes alight receiving portion of the optical unit 130 (a convex surface of alens in the illustrated example) and the second surface 110 b of thesubstrate of the image sensor chip 110. Accordingly, the outerconnection pads 116 of the image sensor chip 110 are also exposed by thehousing 140. Nonetheless, the housing 140 protects the relativelyfragile components, such as the image sensor and optical elements fromimpacts that the module 100 may experience.

The camera module 100 may also include a shielding film 200 on thehousing 140. The shielding film 200 may also extend along an innersurface of the housing 140 that defines the through-hole 142. Theshielding film 200 is of material, known per se, that blockselectromagnetic waves. That is, shielding film 200 prevents the cameramodule 100 from experiencing electromagnetic interference.

As shown in the figures, the camera module 100 may also includeconductive structure 210 occupying the through-hole 142 of the housing140 and the recess 122 of the transparent member 120. In this case, theconductive structure 210 extends through the side of the housing 140 andcovers the ground pad 112 of the image sensor chip 110 disposed on thefirst surface 110 a. Thus, circuitry of the image sensor chip 110 can bereadily grounded via the ground pad 112 and conductive structure 210.Furthermore, the conductive structure 210 may electrically connect theshielding film 200 to the ground pad 112.

In the embodiment of a camera module as described above, one of theconductive pads formed on the first surface 110 of the substrate of theimage sensor chip 110 is dedicated for use as a ground pad. Thus, theground pad 112 does not require a via in contrast to a conventional casein which the ground pad is formed on the exposed surface of thesubstrate. Therefore, the inventive concept allows for a freer designfor the layout of the vias extending through the substrate of the imagesensor chip. Also, the structure for allowing electronic circuitry ofthe image sensor chip to be grounded is relatively simple

A method of manufacturing a camera module in accordance with theinventive concept will now be described with reference to FIGS. 4 to 8.

Referring first to FIG. 4, to an image sensor chip 110 is provided, anda transparent member 120 is adhered to the image sensor chip 110.

In an example of this process, first, dies are demarcated on a wafer byscribe lines, for example (not illustrated). The dies may be defined atregular intervals across the wafer. Each die has a ground pad and aplurality of chip pads on an active surface thereof. The dies areseparated from one another by sawing the wafer (along the scribe lines),and then each respective die is processed to form/complete an imagesensor chip.

A glass substrate may be adhered to the wafer before the sawing processis performed. At this time, the glass substrate has one or more recessestherein at a position(s) corresponding to (i.e., over) the ground padsof the image sensor chips to be formed. In this case, the recess(es) inthe glass substrate are located along respective ones of the scribelines. Thus, the glass substrate is sliced along with the wafer duringthe sawing process. The slicing of the glass substrate exposes therecess(es) along the cuts. As a result, the respective image sensorchips 110 are formed, each image sensor chip 110 has a transparentmember 120 adhered thereto, and an outer peripheral edge portion of eachtransparent member 120 has a stepped shaped defining a recess thatexposes a ground pad 112 of the chip 110 to which it is adhered.

As is also illustrated in FIG. 4, the image sensor chip 110 includes asubstrate having a first surface 110 a constituting an active surface ofthe chip where circuit elements of the image sensor chip are located.The ground pad 112 and a plurality of chip pads 114 (refer back to FIG.3) are disposed on the first surface 110 a. In the example of the imagesensor chip 110 described above, respective ones of the pads, includingthe ground pads 112, are disposed along an outer peripheral portion ofthe image sensor chip 110. As was also mentioned above, the image sensorchip 110 may have outer connection pads 116 on a second surface 110 b ofthe substrate of the chip 110, and conductive vias extending through thesubstrate and electrically connecting the chip pads 114 to the outerconnection pads 116.

Referring to FIG. 5, an optical unit 130 is adhered to the transparentmember 120. As was described above, the optical unit 130 may include atleast one lens for guiding light from an object to the image sensor chip110. Accordingly, the optical unit 130 may focus light from the objectonto the image sensor chip 110.

Referring to FIG. 6, the image sensor chip 110, the transparent member120 and the optical unit 130 are accommodated in a housing 140 having athrough-hole 142. At this time, the through-hole 142 is in opencommunication with and, more specifically, is aligned with the recess122 in the transparent member 120. Accordingly, the ground pad 112 ofthe image sensor chip 110 is exposed by the through-hole 142 and therecess 122.

A shielding film 200 is formed on an outer surface of the housing 140including the surface that defines the through-hole 142. The shieldingfilm 200 shields the components within the housing 140 fromelectromagnetic radiation. In particular, the housing 140 and shieldingfilm 200 thereon surround the image sensor chip 110 to prevent strayelectromagnetic radiation from neighboring devices, for example, frominterfering with the operation of the circuitry of the chip 110, i.e.,to prevent the camera module from experiencing electromagneticinterference.

Referring to FIG. 7, the conductive structure 210 is formed toelectrically connect the shielding film 200 and the ground pad 112 ofthe image sensor chip 110. In an example of this process, conductivematerial is dispensed into the through-hole 142 and the recess 122 toform the conductive structure 210. The conductive material may be solderpaste or conductive epoxy resin.

Referring to FIG. 8, outer connection members 320 such as solder ballsare formed on the outer connection pads 116 and the image sensor chip110. As is also shown in FIG. 8, the camera module so completed may bemounted to a circuit board 300. For example, the outer connectionmembers 320 are disposed on and bonded to bonding pads 310 of thecircuit board 300 to electrically connect the image sensor chip 110 andthe circuit board 300.

As was described in detail above, a camera module in accordance with theinventive concept includes a housing surrounding an image sensor chip,and an electromagnetic wave-shielding film on an outer surface of thehousing and surrounding (extending around the side of) the image sensorchip. Therefore, the image sensor chip is protected from external impactand electromagnetic interference between the camera module and anadjacent electronic device can be prevented.

In addition, a ground pad of the image sensor chip is formed on the samesurface of the substrate of the image sensor chip as the chip pads.Therefore, a via is not required for the ground pad. Thus, it iseconomical to manufacture a camera module according to the inventiveconcept is.

Finally, embodiments of the inventive concept have been described abovein detail. The inventive concept may, however, be embodied in manydifferent forms and should not be construed as being limited to theembodiments described above. Rather, these embodiments were described sothat this disclosure is thorough and complete, and fully conveys theinventive concept to those skilled in the art. Thus, the true spirit andscope of the inventive concept is not limited by the embodimentsdescribed above but by the following claims.

What is claimed is:
 1. A method of manufacturing a camera module,comprising: providing an image sensor chip including a substrate havingfirst and second opposite surfaces, and a ground pad on the firstsurface of the substrate; providing a housing having a through-holeextending through a side thereof; providing a transparent member;providing the housing with an electromagnetic wave-shielding film;assembling the image sensor chip and the transparent member to thehousing such that the first surface of the substrate of the image sensorchip faces the interior of the housing, the transparent member isdisposed on the first surface of the substrate, the second surface ofthe substrate of the image sensor chip is exposed to the environmentoutside the housing, and the ground pad is exposed to the environmentoutside the housing via the through-hole in the housing; and forming anelectrical conductor that is electrically connected to the ground padincluding by filling the through-hole with conductive material.
 2. Themethod of claim 1, wherein the assembling comprises adhering thetransparent member to the image sensor chip with the transparent memberdisposed on the first surface of the substrate of the chip, and theninserting the image sensor chip and the transparent member adheredthereto into the housing.
 3. The method of claim 2, further comprisingdisposing an optical unit on the transparent member such that the imagesensor chip, the transparent member and the optical unit have the formof a pillar, and wherein the assembling comprises inserting the pillarconstituted by the image sensor chip, the transparent member and theoptical unit into the housing.
 4. The method of claim 1, wherein thetransparent member has a recess in a surface thereof constituting theopening, and the assembling comprises setting the ground pad within therecess and such that the recess is aligned with the through-hole in thehousing, whereby the ground pad is exposed to the environment outsidethe housing via the through-hole in the housing and the recess in thetransparent member.
 5. The method of claim 1, wherein the providing thehousing with the electromagnetic wave-shielding film comprises formingthe electromagnetic wave-shielding film on an outer surface of thehousing.
 6. The method of claim 5, wherein the providing the housingwith the electromagnetic wave-shielding film comprises forming theelectromagnetic wave-shielding film on a surface the housing thatdefines the through-hole before the conductor is formed such that theground pad is electrically conductively connected to the electromagneticwave-shielding film by the conductor once it is formed.